The demand for blood and blood derivatives is increasing all over the world. In high income countries, in particular, the rate of growth in demand has been rising so rapidly that shortages have begun to appear in a number of countries. In all Western countries, demand is growing much faster than rates of growth in populations aged 18-65 from whom donors are drawn. And, despite a massive research effort in the United States to find alternatives, it remains true that: ‘In medicine, there is no substitute for human blood.’

In later chapters some evidence and illustrations are given of shortages of supply in the United States, Japan and other countries and of attempts that have been made on a commercial basis to import blood to meet rising demands. It is not possible, however, to estimate in any precise way national trends in demand for blood and blood derivatives. Statistical indicators are few and generally inadequate as they rarely take account of the unmet needs in a population for medical and surgical treatment (partly because of deficiencies in a country's medical services). Similarly, little is known on a national basis in many countries about the potential demand, if supplies were adequate, for blood and blood derivatives to be used for preventive and therapeutic purposes. Some examples are given later of shortages and unmet needs of these kinds among particular groups in national populations.

In the absence of estimates of demand, we have to turn to examine trends in the statistics relating to the collection and use of blood, and to such evidence as is available concerning hospital shortages, the postponement of surgical operations and other indices. Much of this evidence is included in Chapter 4. Meanwhile, however, to provide a general picture of the growth in demand we give certain overall figures for England and Wales, the United States and Sweden. They are taken from a variety of sources cited in Chapter 4.

Between 1948 (when the National Health Service was established) and 1967 the annual number of donations of blood in England and Wales rose by 269 per cent or from 9 per 1,000 total population to 29 per 1,000.